The treatment of diffuse distal coronary artery disease is presently unsatisfying. Coronary artery bypass grafting (CABG) is usually not successful in these circumstances. Mechanical endarterectomy of a distal coronary artery combined with CABG has been performed 26 times at the NIH. Followup catheterization six months after operation revealed that 14 of the 20 grafts studied were patent (70%). Sixteen endarterectomies were performed to the distal right coronary artery, two to the distal left anterior descending coronary artery, and one each to the circumflex and diagonal coronary arteries. The average flow in these patent grafts at the time of operation was 87 ml/min (range 30-200 ml/min). Intraoperatively, the four nonpatent grafts had average flows of 27 ml/min. All of these 20 patients had concomitant CABG's without endarterectomy to other coronary arteries. There were two perioperative myocardial infarctions. There were no early or late deaths.